This specification relates to digital information retrieval, and particularly to processing search results.
The Internet enables access to a wide variety of resources, such as video or audio files, web pages for particular subjects, book articles, or news articles. A search engine can identify resources in response to a user query that includes one or more search terms or phrases. The search engine ranks the resources based on their relevance to the query and importance and provides search results that link to the identified resources. The search results are typically ordered according to the rank. One example search engine is the Google™ search engine provided by Google Inc. of Mountain View, Calif., U.S.A.
In addition to ordering search results based on the rank of the resources identified response to the query, the search results can be further ordered based on user history data for a user and a profile for the user. If a user has granted permission to let the search engine collect user history data and/or has created a user profile for the search engine, the search engine can process this data to infer user preferences for sites. The search engine uses these inferred user preferences for sites to adjust the order of the search results so that search result that are more likely to be of interest to the user are higher in the order than other search results.
Processes for inferring user preferences for sites, however, may often require a high confidence measure of a user being interested in a particular site before that site is identified as a preferred site. As the user history data on which such inferences are based are inherently noisy data (i.e., click data, bookmarks created for unknown intent), a high confidence measure reduces the likelihood that an inferred user preference for a site is erroneous. However, there are some sites that may be of interest to the user that are never inferred as a preferred site because a high confidence measure for these sites cannot be established. Likewise, inferences can only be drawn where there is evidence to do so. For example, a user might prefer search results that reference a particular company, but if the user never sees that company in a search result, that preference is unlikely to be inferred.